1. Field
The following description generally relates to an optical device recording or reproducing data on an optical device and an adjusting method thereof.
2. Description of the Related Art
In general, an optical disk refers to CD (Compact Disc)-ROM, CD-R, CE-RW, DVD (Digital Versatile Disc)-ROM, DVD-R, DVD-RW, and a recently-developed format of AVCHD, HD-DVD, and a Blu-ray Disc® using a bluish-violet laser light capable of higher density recording than the above optical discs, such as BD-R and BD-RE.
Data is recorded or reproduced on the optical disk by an optical pickup including a laser diode as a light emitting source, a photo diode as a light receiving source, a diffraction grating forming a light path between the light emitting source and the light receiving source, a sensor lens, a mirror, and an objective lens.
In the objective lens of the optical pickup, a focusing servo control is performed on a perpendicular direction of the optical disk, and a tracking servo control is performed on a circumferential direction of the optical disk. In the optical pickup, a track is traced, along a track formed along a circumferential direction of the optical disk, to input and output an optical signal corresponding to a pitch shape of a particular track.
The optical disk placed on a tray is loaded on or unloaded from an optical device, and rotated by a spindle motor. The optical pickup is connected to a feed motor to linearly move to a radial direction of the optical disk along a guide rod. The spindle motor includes a stator wound with a coil and fixed to a bracket, and a rotor mounted with a magnet generating an electromagnetic force by interacting with the stator.
In many instances, a problem may occur on a tracking servo or a focusing servo, if a skew angle, which is an angle of inclination or tilt angle (hereinafter referred to as tilt angle) of a rotation shaft in the spindle motor is twisted.